Here is the source. A campfire that burnt into peat soil and was not properly extinguished. It burnt under ground and re-emerged 10m away to cause the wildfire. It has burnt away most of the soil in this part of the island.
Despite the obvious burnt area, there have been two recent camp fires in the area of the wildfire from last year including this one that was in the fire break that was cut to stop the fire spreading to the rest of the island along with neat stacks of wood!
SOAC says you should not have a fire in a woodland or on peaty soil. That means it is inappropriate to have any open fire on Loch Maree islands.
The need to have a camp fire seems to be growing, perhaps not helped by the media showing camping with camp fires like this one, and TV shows that encourage open fires.